Grinding burr



June 8,1926. "1,587,863

' G. W. RYNDERS GRINDING BURR Filed July 26. 1923 2 Sheets-Sheet 1 ATTORNEY G. W. RYNDERS June 8 1926.

GRINDING BURR Filed July 26.1923 2 Sheets-Sheet 2- INVENTOR 650E611 W/Bwams AfioRNEY Patented June 8, 1926.

UNITED STATES- PATENT FECE.

GEORGE W. BYNDERS, OF BELOIT, WISCONSIN. ASSIGNOR TO FAIRBANKS, MORSE & 00., OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

GRINDING BURR.

Application filed July 26, 1923.

My invention relates to improvements in grinding burrs and, more particularly, to a novel arrangement of grinding ribs 011 burrs.

The object of my invention is to so an range the grinding ribs that the material to be ground will be forced progressively outward from the inner edge of the burr and, at the same time, provide for an equally efficient grinding of diverse kinds of materials. The advantages of such an arrangement of ribs are evident for it secures a more steady and continuous griding process and is equally good 011 Widely varying classes of material. Other advantages will appear from the following drawings and description of my device.

My novel arrangement of grinding ribs will be more clearly understood by referring to the following drawings, where Fig. 1 represents a plan View of a grinding burr with my arrangement of ribs, and Fig. 2 is an enlarged fragmentary section of the same burr showing more clearly how the grinding ribs are positioned.

Referring by numerals to the drawings the positions of the grinding ribs (5) are lo cated by the intersections of the concentric circles (6) with tangential arcs (7). The circles (6) have, as their common center, the center of the periphery of the grinding burr. The radius for the tangential arcs (7) is the diameter of the inner rim of the burr and the center of these arcs are at equally spaced intervals (11) around the inner rim of the burr.

The cutting edges (8) of the rinding ribs (5) are located on tangents 9) drawn to concentric circles (10) with the center of the burr as their common center. The tangent for the outer rib being the one drawn to the innermost circle, the tangent to the second from the outer rib being the one drawn from the second inner circle and so forth. It will be seen, therefore, that the cutting edges (8) form progressively diminishing angles with the radial to the burr as the grinding ribs (5) approach the periphery of the burr. It will also be seen that the ribs (5) are independent of one another and are preferably angular in shape. The ribs 5 are preferably arranged so that they will fall. into groups, each group preferably consisting of a series of ribs, the shearing edge 8 of each Serial No. 653,953.

rib in a series substantially terminating in any one of the tangential arcs 7.

What I claim as new and desire to obtain by Letters Patent is:

1. In a grinding burr, a plurality of independent grinding ribs arranged in groups and having shearing edges substantially coinciding with tangential lines drawn to circles concentric with the periphery of the burr, the shearing edges of corresponding ribs in adjacent groups being angularly disposed with respect to each other.

2. In a grinding burr, a plurality of independent grinding ribs arranged in groups and having shearing edges substantially coinciding with the tangential lines drawn to circles concentric with the periphery of the burr, the shearing edges of the ribs in any one group being angularly disposed with respect to each other.

3. In a grinding burr, a plurality of independent angular grinding ribs, shearing edges on said ribs, said shearing edges making substantially progressively lesser angles with the radial to said burr, as such ribs approach the peripher of said burr.

4. In a grinding burr, a plurality of in dependent grinding ribs arranged in groups and havin shearing edges substantially coinciding Wlfil tangential lines drawn to circles concentric with the periphery of the burr, said tangents being drawn from circles having progressively smaller diameters as the ribs approach the periphery of the burr.

b. In a grinding burr, a plurality of independent angular grinding ribs having shearing edges and arranged in evenly spaced groups about the surface of said burr, the inner termini of the shearing edges of the ribs in any group being located sub stantially on a tangential are drawn from the inner edge of the burr, the termini of the shearing edges of the correspondln ribs in said groups being substantially located on a circle concentric with the inner edge of the burr.

6. In a grinding burr, a plurality of independent grinding ribs having shearing edges and arranged in groups, the inner termini of the shearing edges of the ribs in any one group being located substantially on a tangential are drawn from the inner edge of the burr, said shearingedges making substantially progressively lesser angles with the radial to said burr as said ribs approach the periphery of said disc.

7. In a grinding burr, a plurality of acute angled shearing members disposed thereon in circles concentric With the periphery of said burr, the shearing members on each of said circles being offset with respect to the shearing members on adjacent circles and having their acute angles disposed in the same direction a plurality of parallel ribs disposed on a circle concentric With and offset to the innermost circle of angular shearing members and a plurality of obtuse angled ribs having the obtuse an gle extending opposite in direction to the acute angles of the first named shearing members, the cutting edges 01 said obtuse angled members bein alternated by parallel ribs disposed offset to the parallel ribs of the last named circle of parallel ribs.

8. In a grinding burr a plurality of acute angled shearing members disposed thereon in circles concentric with the periphery of said burr, the shearing members on each of said circles being offset With the respect to the shearing members on adjacent circles and having their acute angles disposed in the same direction, a plurality of par llel ribs disposed on a circle concentric vith and offset to the innermost circle of angular shearing members and a plurality of obtuse angled ribs having the obtuse angle extending opposite in direction to the acute angles of the first-named shearing members, the cutting edges of said obtuse angled members being alternated by parallel ribs disposed oiiset to the parallel ribs of the lastnamed circle of parallel ribs, the shearing edges of all of said ribs making substantially progressively lesser angles with the radial to said burr as the ribs approach the periphery of said burr.

GEORGE W. RYNDERS. 

